The present invention relates to dehumidifiers. More particularly, the present invention relates to a hygroscopic material having a shape and surface area orientation which facilitates circulation and drying of a working gas.
Dehumidifiers are used to dry working gases, such as water vapor in air. Typical desiccant dehumidifying machines blow the air or working gas across a desiccant material to remove the vapor from the working gas. These types of machines require a power source and typically utilize moving parts to dry the working space. In addition, the desiccant is typically contained or packaged within the machine and the vapor rich air is mechanically passed across the desiccant. In addition to requiring active intervention to turn the machine ON and OFF, such devices are limited by their power needs, the breakdown of the moving mechanical components, and a somewhat inefficient use of the desiccant material.
Accordingly, the present invention provides a shaped monolithic hygroscopic material which moves air through a xe2x80x9cchimney effectxe2x80x9d or air density differences in and around the material. The present invention thus provides a passive dehumidifier which allows direct contact with the gas being dried without the need for an outside power source, moving parts, or packaging of a desiccant material. Alternatively, the tendency of the material to seek equilibrium with the working gas may also be utilized to achieve humidification.
The present invention comprises a hygroscopic material having at least one passageway or channel therethrough. The material is shaped to provide a surface area to facilitate gas flow, and drying of an ambient gas by creating a chimney effect which facilitates mixing of the gas. This causes the heavier water vapor or other compound containing gas to contact adsorbent material adjacent to the passageway or channel, adsorb at least some of the compound, and cause the lighter gas to exit the passageway or channel. The dehumidifier may have various shapes and sizes and can be reactivated to restore its drying capacity. When utilized as a humidifier, the material desorbs or adds the constituent (such as water vapor) to the gas and a downdraft rather than a chimney effect is achieved.